The kleptoparasitism -from the Greek klepto, to steal- is a form of feeding in which an animal takes advantage of the captures of another animal or of the materials or objects that it has used to form its nest or burrow.
In a simple way, kleptoparasitism can be classified into intraspecificwhen the parasite steals from its own species, or interspecificwhen it does to animals of other species.
This form of piracy is rare among birds, despite which there are some species that do it repeatedly to obtain food, such as skuas or frigatebirds, and others that do it opportunistically. In this second group we find seagulls, coots and some ducks. Among raptors, the red kite shines in a special way.
The outlaw of the air
The milan real (Kite kite) is one of the easiest diurnal birds of prey (from the Latin rapere, to seize by force) to differentiate with the naked eye, thanks to its reddish-orange color, which becomes more ocher in the belly area, to its long elbowed wings with a white spot and a fork-shaped tail, which gives it a very characteristic silhouette.
Both its height and its physiognomy are similar to those of the black kite, from which it differs by the grayish color of its head. The red kite lives in countryside with forests, fields and scrubland, and when night falls the specimens gather in colonies within the wooded areas.
Its flight is harmonious, elegant and displays a spectacular mastery of acrobatics. It could be said that he is a true master of aerial dribbling, a skill that allows him to harass other birds and steal their hard-earned catches mid-air.
A privileged view
Birds of prey are the animals with the most highly developed visual acuity, approximately twice that of humans. This is fundamentally due to three facts: his eye is very elongated (tubular), which allows the image to be amplified; its pupil is considerably larger, which translates into less diffraction; and its density of photoreceptors is higher, which implies a higher optical resolution. To all this, we must add that some diurnal birds of prey have two foveas – the eye of the eye.
The visual system of the red kite is endowed with these singularities with the exception of the double fovea, it only has one on each retina, possibly because it combines hunting with the consumption of carrion. What he does have is a vision tetrachromaticYou have a fourth cone on your retina that is sensitive to wavelengths beyond blue.
All these characteristics allow the red kite to distinguish colors with great sharpness, to have a truly privileged image resolution and focus.
Nature has also endowed them with a depth vision system and the ability to perceive the movement of prey from a certain height, being able to process up to sixty images per second.
Last but not least, the insertion of the eyes in the face is not completely frontal, the eyeballs are arranged at an angle of thirty degrees. An evolutionary advantage that gives them a visual field of 340º, much higher than our 180º.